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| author | Eric Sandeen <sandeen@redhat.com> | 2008-07-11 19:27:31 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2008-07-11 19:27:31 -0400 |
| commit | e4079a11f5ed966b7d972cc69e8d337a0f095e32 (patch) | |
| tree | 1e70276654b4808cfcde549c7f2612947e5ab1c3 /fs/ext4/super.c | |
| parent | c07651b556323e0e763c452587fe29d2b034b314 (diff) | |
| download | lwn-e4079a11f5ed966b7d972cc69e8d337a0f095e32.tar.gz lwn-e4079a11f5ed966b7d972cc69e8d337a0f095e32.zip | |
ext4: do not set extents feature from the kernel
We've talked for a while about getting rid of any feature-
setting from the kernel; this gets rid of the code which would
set the INCOMPAT_EXTENTS flag on the first file write when mounted
as ext4[dev].
With this patch, if the extents feature is not already set on disk,
then mounting as ext4 will fall back to noextents with a warning,
and if -o extents is explicitly requested, the mount will fail,
also with warning.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 2bf9cdd7a036..1cb371dcd609 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1324,6 +1324,13 @@ set_qf_format: clear_opt(sbi->s_mount_opt, NOBH); break; case Opt_extents: + if (!EXT4_HAS_INCOMPAT_FEATURE(sb, + EXT4_FEATURE_INCOMPAT_EXTENTS)) { + ext4_warning(sb, __func__, + "extents feature not enabled " + "on this filesystem, use tune2fs\n"); + return 0; + } set_opt (sbi->s_mount_opt, EXTENTS); break; case Opt_noextents: @@ -1997,12 +2004,18 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent) /* * turn on extents feature by default in ext4 filesystem - * User -o noextents to turn it off + * only if feature flag already set by mkfs or tune2fs. + * Use -o noextents to turn it off */ - set_opt(sbi->s_mount_opt, EXTENTS); + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) + set_opt(sbi->s_mount_opt, EXTENTS); + else + ext4_warning(sb, __func__, + "extents feature not enabled on this filesystem, " + "use tune2fs.\n"); /* - * turn on mballoc feature by default in ext4 filesystem - * User -o nomballoc to turn it off + * turn on mballoc code by default in ext4 filesystem + * Use -o nomballoc to turn it off */ set_opt(sbi->s_mount_opt, MBALLOC); |